Torque converter lockup clutch backing plate

ABSTRACT

A backing plate assembly includes a front cover and a rear cover. The front cover defines an inner surface and a front plane, and the rear cover terminates at a lip. A backing plate forms a body having an outer surface that terminates at a base portion. When the outer surface is coupled to the inner surface, the backing plate is rotationally but not axially coupled to the front cover. The lip contacts the base portion to define a maximum axial distance between the backing plate and the front plane.

RELATED APPLICATIONS

The present application claims the benefit of U.S. Patent ApplicationNo. 15/043,878 filed on Feb. 15, 2016 which claims the benefit ofProvisional Application Ser. No. 62/117,139, filed on Feb. 17, 2015, thedisclosures of which are hereby expressly incorporated by reference intheir entirety.

FIELD OF THE DISCLOSURE

The present disclosure relates to a transmission system, and inparticular to a lockup clutch assembly of a torque converter for thetransmission system.

BACKGROUND

A torque converter is a fluid coupling device that is used to transferrotating power from a power unit, such as an engine or electric motor,to a power-transferring device such as a transmission. A torqueconverter can have a clutch system to allow the torque converter to beselectable for either fluid coupling or mechanical coupling depending onthe engagement of the clutch system. The transmission is an apparatusthrough which power and torque can be transmitted from a vehicle's powerunit to a load-bearing device such as a drive axis. Conventionaltransmissions include a variety of gears, shafts, and clutches thattransmit torque therethrough.

SUMMARY

In a first embodiment, a backing plate assembly includes a front coverand a rear cover, the front cover defining an inner surface and a frontplane, and the rear cover terminating at a lip; and a backing plateforming a body having an outer surface that terminates at a baseportion; wherein, when the outer surface is coupled to the innersurface, the backing plate is rotationally but not axially coupled tothe front cover; further wherein, the lip contacts the base portion todefine a maximum axial distance between the backing plate and the frontplane.

In one example of this embodiment, the outer surface and the innersurface include splines. In a second example, the splines allow thebacking plate to move axially relative to the front cover. In a thirdexample, the front cover can be coupled to the rear cover at more thanone axial distance from the front plane. In a fourth example, a clutchassembly is located between the front cover and the rear cover; whereinthe location of the backing plate affects the engagement of the clutchassembly. In a fifth example, at least one bearing is disposed betweenthe front cover and the rear cover; wherein the rear cover can be spacedaxially from the front plane to set clearances for the bearing.

In another embodiment, a torque converter lockup clutch backing plateincludes a backing plate assembly having a backing plate surface coupledto a splined outer wall; a front cover having a splined inner wall; aback cover having a lip; a damper having an outer surface; and a clutchassembly that mechanically couples the backing plate surface to thedamper when the clutch assembly is in an engaged position; wherein, thesplined outer wall rotationally couples the backing plate assembly tothe splined inner wall; further wherein the backing plate assembly canmove axially when the splined outer wall rotationally couples thebacking plate assembly to the splined inner wall of the front cover.

In one example, the lip contacts a portion of the backing plate assemblyto set a maximum axial distance the backing plate assembly can move fromthe front cover. In a second example, the back cover and the front covercan be coupled to one another at a plurality of different axialdistances from one another. In a third example, the axial alignment ofthe front cover and the back cover changes the axial alignment of thebacking plate assembly relative to the front cover. In a fourth example,tolerances of the clutch assembly are set by changing the axialalignment of the lip. In a fifth example, a piston is provided that isactuated to selectively engage the clutch assembly. In a sixth example,the piston applies force to the clutch assembly that is resisted by thebacking plate through the lip.

In a third example, a method is provided for assembling a torqueconverter assembly. The method includes placing a nose hub on a buildtable so an axis of rotation is perpendicular to a level surface of thebuild table; axially aligning a front cover with the nose hub andplacing the front cover onto the nose hub; coupling the front cover tothe nose hub; placing a piston and at least one clutch plate or reactionplate into the front cover; placing a damper in the front cover inalignment with the clutch plate or reaction plate; aligning a backingplate with splines in the front cover and placing the backing plate intothe front cover; placing a first bearing onto a back portion of the nosehub; axially aligning a turbine assembly with the nose hub and placingthe turbine assembly against the first bearing; placing a second bearingonto a hub of the turbine assembly; axially aligning a stator assemblywith the nose hub and placing the stator assembly on the second bearing;placing a third bearing onto a hub of the stator assembly; axiallyaligning a rear cover with the nose hub and placing the rear cover ontothe third bearing; and setting clearances for a clutch assembly bylifting the rear cover a desired distance away from the front coverbefore coupling the rear cover to the front cover.

In one example of this embodiment, the desired distance is a distancethat allows the clutch assembly to mechanically transfer torsional forcewhen in an engaged position. In a second example, the desired distanceis also a distance that allows the clutch assembly to be oriented in adisengaged state where torsional force will not be transferred throughthe clutch assembly. In a third example, the setting clearances for aclutch assembly step also includes setting clearances for the first,second, and third bearing. In a fourth example, the coupling the rearcover to the front cover step involves welding the rear cover to thefront cover. In a fifth example, the torque converter is mounted to atransmission after the coupling the rear cover to the front cover step.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned aspects of the present disclosure and the manner ofobtaining them will become more apparent and the disclosure itself willbe better understood by reference to the following description of theembodiments of the disclosure, taken in conjunction with theaccompanying drawings, wherein:

FIG. 1 is an exemplary block diagram and schematic view of oneillustrative embodiment of a powered vehicular system;

FIG. 2 is a top half cross-sectional view of a conventional torqueconverter;

FIG. 3 is a top half cross-sectional view of a torque converter with abacking plate assembly as disclosed herein;

FIG. 4 is a perspective view of the backing plate assembly of FIG. 3;

FIG. 5 is a partial cross-sectional perspective view of the backingplate assembly of FIG. 4; and

FIG. 6 is a flow diagram of a process for assembling a torque converter.

Corresponding reference numerals are used to indicate correspondingparts throughout the several views.

DETAILED DESCRIPTION

The embodiments of the present disclosure described below are notintended to be exhaustive or to limit the disclosure to the preciseforms disclosed in the following detailed description. Rather, theembodiments are chosen and described so that others skilled in the artmay appreciate and understand the principles and practices of thepresent disclosure.

The terminology used herein is for the purpose of describing particularillustrative embodiments only and is not intended to be limiting. Asused herein, the singular forms “a”, “an” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. Similarly, plural forms may have been used to describeparticular illustrative embodiments when singular forms would beapplicable as well. The terms “comprises,” “comprising,” “including,”and “having,” are inclusive and therefore specify the presence of statedfeatures, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof. The method steps, processes, and operations described hereinare not to be construed as necessarily requiring their performance inthe particular order discussed or illustrated, unless specificallyidentified as an order of performance. It is also to be understood thatadditional or alternative steps may be employed.

Referring now to FIG. 1, a block diagram and schematic view of oneillustrative embodiment of a vehicular system 100 having a drive unit102 and transmission 118 is shown. In the illustrated embodiment, thedrive unit 102 may include an internal combustion engine, diesel engine,electric motor, or other power-generating device. The drive unit 102 isconfigured to rotatably drive an output shaft 104 that is coupled to aninput or pump shaft 106 of a conventional torque converter 108. Theinput or pump shaft 106 is coupled to an impeller or pump 110 that isrotatably driven by the output shaft 104 of the drive unit 102. Thetorque converter 108 further includes a turbine 112 that is coupled to aturbine shaft 114, and the turbine shaft 114 is coupled to, or integralwith, a rotatable input shaft 124 of the transmission 118. Thetransmission 118 can also include an internal pump 120 for buildingpressure within different flow circuits (e.g., main circuit, lubecircuit, etc.) of the transmission 118. The pump 120 can be driven by ashaft 116 that is coupled to the output shaft 104 of the drive unit 102.In this arrangement, the drive unit 102 can deliver torque to the shaft116 for driving the pump 120 and building pressure within the differentcircuits of the transmission 118.

The transmission 118 can include a planetary gear system 122 having anumber of automatically selected gears. An output shaft 126 of thetransmission 118 is coupled to or integral with, and rotatably drives, apropeller shaft 128 that is coupled to a conventional universal joint130. The universal joint 130 is coupled to, and rotatably drives, anaxle 132 having wheels 134A and 134B mounted thereto at each end. Theoutput shaft 126 of the transmission 118 drives the wheels 134A and 134Bin a conventional manner via the propeller shaft 128, universal joint130 and axle 132.

A conventional lockup clutch 136 is connected between the pump 110 andthe turbine 112 of the torque converter 108. The operation of the torqueconverter 108 is conventional in that the torque converter 108 isoperable in a so-called “torque converter” mode during certain operatingconditions such as vehicle launch, low speed and certain gear shiftingconditions. In the torque converter mode, the lockup clutch 136 isdisengaged and the pump 110 rotates at the rotational speed of the driveunit output shaft 104 while the turbine 112 is rotatably actuated by thepump 110 through a fluid (not shown) interposed between the pump 110 andthe turbine 112. In this operational mode, torque multiplication occursthrough the fluid coupling such that the turbine shaft 114 is exposed todrive more torque than is being supplied by the drive unit 102, as isknown in the art. The torque converter 108 is alternatively operable ina so-called “lockup” mode during other operating conditions, such aswhen certain gears of the planetary gear system 122 of the transmission118 are engaged. In the lockup mode, the lockup clutch 136 is engagedand the pump 110 is thereby secured directly to the turbine 112 so thatthe drive unit output shaft 104 is directly coupled to the input shaft124 of the transmission 118, as is also known in the art.

The transmission 118 further includes an electro-hydraulic system 138that is fluidly coupled to the planetary gear system 122 via a number,J, of fluid paths, 140 ₁-140 _(J), where J may be any positive integer.The electro-hydraulic system 138 is responsive to control signals toselectively cause fluid to flow through one or more of the fluid paths,140 ₁-140 _(J), to thereby control operation, i.e., engagement anddisengagement, of a plurality of corresponding friction devices in theplanetary gear system 122. The plurality of friction devices mayinclude, but are not limited to, one or more conventional brake devices,one or more torque transmitting devices, and the like. Generally, theoperation, i.e., engagement and disengagement, of the plurality offriction devices is controlled by selectively controlling the frictionapplied by each of the plurality of friction devices, such as bycontrolling fluid pressure to each of the friction devices. In oneexample embodiment, which is not intended to be limiting in any way, theplurality of friction devices include a plurality of brake and torquetransmitting devices in the form of conventional clutches that may eachbe controllably engaged and disengaged via fluid pressure supplied bythe electro-hydraulic system 138. In any case, changing or shiftingbetween the various gears of the transmission 118 is accomplished in aconventional manner by selectively controlling the plurality of frictiondevices via control of fluid pressure within the number of fluid paths140 ₁-140 _(J).

The system 100 further includes a transmission control circuit 142 thatcan include a memory unit 144. The transmission control circuit 142 isillustratively microprocessor-based, and the memory unit 144 generallyincludes instructions stored therein that are executable by a processorof the transmission control circuit 142 to control operation of thetorque converter 108 and operation of the transmission 118, i.e.,shifting between the various gears of the planetary gear system 122. Itwill be understood, however, that this disclosure contemplates otherembodiments in which the transmission control circuit 142 is notmicroprocessor-based, but is configured to control operation of thetorque converter 108 and/or transmission 118 based on one or more setsof hardwired instructions and/or software instructions stored in thememory unit 144.

In the system 100 illustrated in FIG. 1, the torque converter 108 andthe transmission 118 include a number of sensors configured to producesensor signals that are indicative of one or more operating states ofthe torque converter 108 and transmission 118, respectively. Forexample, the torque converter 108 illustratively includes a conventionalspeed sensor 146 that is positioned and configured to produce a speedsignal corresponding to the rotational speed of the pump shaft 106,which is the same rotational speed of the output shaft 104 of the driveunit 102. The speed sensor 146 is electrically connected to a pump speedinput, PS, of the transmission control circuit 142 via a signal path152, and the transmission control circuit 142 is operable to process thespeed signal produced by the speed sensor 146 in a conventional mannerto determine the rotational speed of the turbine shaft 106/drive unitoutput shaft 104.

The transmission 118 illustratively includes another conventional speedsensor 148 that is positioned and configured to produce a speed signalcorresponding to the rotational speed of the transmission input shaft124, which is the same rotational speed as the turbine shaft 114. Theinput shaft 124 of the transmission 118 is directly coupled to, orintegral with, the turbine shaft 114, and the speed sensor 148 mayalternatively be positioned and configured to produce a speed signalcorresponding to the rotational speed of the turbine shaft 114. In anycase, the speed sensor 148 is electrically connected to a transmissioninput shaft speed input, TIS, of the transmission control circuit 142via a signal path 154, and the transmission control circuit 142 isoperable to process the speed signal produced by the speed sensor 148 ina conventional manner to determine the rotational speed of the turbineshaft 114/transmission input shaft 124.

The transmission 118 further includes yet another speed sensor 150 thatis positioned and configured to produce a speed signal corresponding tothe rotational speed of the output shaft 126 of the transmission 118.The speed sensor 150 may be conventional, and is electrically connectedto a transmission output shaft speed input, TOS, of the transmissioncontrol circuit 142 via a signal path 156. The transmission controlcircuit 142 is configured to process the speed signal produced by thespeed sensor 150 in a conventional manner to determine the rotationalspeed of the transmission output shaft 126.

In the illustrated embodiment, the transmission 118 further includes oneor more actuators configured to control various operations within thetransmission 118. For example, the electro-hydraulic system 138described herein illustratively includes a number of actuators, e.g.,conventional solenoids or other conventional actuators, that areelectrically connected to a number, J, of control outputs, CP₁-CP_(J),of the transmission control circuit 142 via a corresponding number ofsignal paths 72 ₁-72 _(J), where J may be any positive integer asdescribed above. The actuators within the electro-hydraulic system 138are each responsive to a corresponding one of the control signals,CP₁-CP_(J), produced by the transmission control circuit 142 on one ofthe corresponding signal paths 72 ₁-72 _(J) to control the frictionapplied by each of the plurality of friction devices by controlling thepressure of fluid within one or more corresponding fluid passageway 140₁-140 _(J), and thus control the operation, i.e., engaging anddisengaging, of one or more corresponding friction devices, based oninformation provided by the various speed sensors 146, 148, and/or 150.

The friction devices of the planetary gear system 122 are illustrativelycontrolled by hydraulic fluid which is distributed by theelectro-hydraulic system in a conventional manner. For example, theelectro-hydraulic system 138 illustratively includes a conventionalhydraulic positive displacement pump (not shown) which distributes fluidto the one or more friction devices via control of the one or moreactuators within the electro-hydraulic system 138. In this embodiment,the control signals, CP₁-CP_(J), are illustratively analog frictiondevice pressure commands to which the one or more actuators areresponsive to control the hydraulic pressure to the one or morefrictions devices. It will be understood, however, that the frictionapplied by each of the plurality of friction devices may alternativelybe controlled in accordance with other conventional friction devicecontrol structures and techniques, and such other conventional frictiondevice control structures and techniques are contemplated by thisdisclosure. In any case, however, the analog operation of each of thefriction devices is controlled by the control circuit 142 in accordancewith instructions stored in the memory unit 144.

In the illustrated embodiment, the system 100 further includes a driveunit control circuit 160 having an input/output port (I/O) that iselectrically coupled to the drive unit 102 via a number, K, of signalpaths 162, wherein K may be any positive integer. The drive unit controlcircuit 160 may be conventional, and is operable to control and managethe overall operation of the drive unit 102. The drive unit controlcircuit 160 further includes a communication port, COM, which iselectrically connected to a similar communication port, COM, of thetransmission control circuit 142 via a number, L, of signal paths 164,wherein L may be any positive integer. The one or more signal paths 164are typically referred to collectively as a data link. Generally, thedrive unit control circuit 160 and the transmission control circuit 142are operable to share information via the one or more signal paths 164in a conventional manner. In one embodiment, for example, the drive unitcontrol circuit 160 and transmission control circuit 142 are operable toshare information via the one or more signal paths 164 in the form ofone or more messages in accordance with a society of automotiveengineers (SAE) J-1939 communications protocol, although this disclosurecontemplates other embodiments in which the drive unit control circuit160 and the transmission control circuit 142 are operable to shareinformation via the one or more signal paths 164 in accordance with oneor more other conventional communication protocols (e.g., from aconventional databus such as J1587 data bus, J1939 data bus, IESCAN databus, GMLAN, Mercedes PT-CAN).

Referring to FIG. 2, one embodiment is shown of a top half,cross-sectional view of a conventional torque converter 200. Torqueconverter 200 includes a front cover assembly 202 fixedly attached to arear cover 204 or shell at a coupled location. In one example, thecoupled location can include a bolted joint, a welded joint, or anyother type of coupling means. The converter 200 includes a turbineassembly 206 with turbine blades, a shell, and a core ring. Theconverter 200 also includes a pump assembly 208 with impellor or pumpblades, an outer shell, and a core ring.

A stator assembly 210 is axially disposed between the pump assembly 208and the turbine assembly 206. The stator assembly 210 can include ahousing, one or more stator blades, and a one-way clutch 212. Theone-way clutch 212 may be a roller or sprag design as is commonly knownin the art.

The torque converter 200 can include a clutch assembly 218 thattransmits torque from the front cover 202 to a turbine hub 214. Theclutch assembly 218 includes a piston plate 216, a backing plate 226, aplurality of clutch plates 220, and a plurality of reaction plates 222.The plurality of clutch plates 220 and reaction plates 222 can besplined to the turbine hub 214, which is bolted to a turbine assembly asshown in FIG. 2. The piston plate 216 can be hydraulically actuated toengage and apply the clutch assembly 218, thereby “hydraulicallycoupling” the turbine assembly 206 and pump assembly 208 to one another.Hydraulic fluid can flow through a dedicated flow passage in the torqueconverter 200 on a front side of the piston plate 216 to urge the plate216 towards and into engagement with the clutch assembly 218. Oneskilled in the art can appreciate how this and other designs offluid-coupling devices can be used for fluidly coupling an engine andtransmission to one another.

Referring now to FIG. 3, a top half, cross-sectional view of a torqueconverter 300 is shown. The torque converter 300 can substantiallyencompass at least one shaft (not shown) about an axis 330. A frontcover 304 may be coupled to a rear cover 306 to partially define aninterior region 328. The front cover 304 may be comprised of a frontplate 332 that extends radially from a nose hub 322 to an outer wall308. The outer wall 308 may be substantially tubular in shape and extendaxially along a portion of the axis 330. The portions of the outer wall308 and the front plate 332 shown in FIG. 3 may revolve 360 degreesabout the axis 330 to partially define the interior region 328. Theouter wall 308 may also have an inner surface 334 along the radiallyinnermost portion of the outer wall 308. In one embodiment, the innersurface 334 may have splines (not shown) extending radially inward fromthe inner surface 334 towards the axis 330.

A backing plate 302 may be disposed in the interior region 328 andextend radially outward relative to the axis 330. The backing plate 302may be slidably coupled to the front cover 304. In this embodiment, theouter wall 308 may have a splined inner surface 334 of the outer wall308 that corresponds to a splined outer surface 402 (FIG. 4) of thebacking plate 302. The backing plate 302 may fit at least partiallywithin the interior region 328 of the front cover 304. Further, thesplined inner surface 334 of the outer wall 308 can slidably couple withthe splined outer surface 402 of the backing plate 302 to substantiallyrestrict independent radial movement between the front cover 304 and thebacking plate 302.

While the splined relationship may prevent radial movement between thefront cover 304 and the backing plate 302, it may allow for at least alimited amount of axial movement of the backing plate 302 relative tothe front cover 304. In one embodiment, the rear cover 306 may contact aportion of the backing plate 302 at a lip 310 when the torque converter300 is fully assembled, as shown in FIG. 3.

A clutch assembly 312 may be partially located between a piston 314 andthe backing plate 302. The piston 314 may be disposed in either anengaged or a disengaged position. In the engaged position, a cavity 316behind the piston 314 may at least partially fill with a fluid (notshown). As fluid and hydraulic pressure builds in the cavity 316, thepiston 314 may slide axially towards the backing plate 302. As thepiston 314 contacts the clutch assembly 312, the clutch assembly 312 maymove axially towards the backing plate 302. The backing plate 302 mayalso move axially until it contacts the lip 310 of the rear cover 306.The axial force applied by the piston 314 may be sufficiently opposed bythe backing plate 302 to force the clutch assembly 312 into an engagedor lockup position.

While the clutch assembly 312 is described above as having limited axialmovement, one skilled in the art will appreciate how the clutch assembly312 may function without any substantial axial movement. For instance,instead of axial movement among the torque converter components, a forcedistribution may achieve substantially the same result. That is to say,the piston 314 may apply a force to the clutch assembly 312 that isresisted by the backing plate 302 through the lip 310 of the rear cover306 without causing any substantial axial movement.

When the clutch assembly 312 is in the engaged position, the front cover304 and a turbine hub 318 may be mechanically coupled to one anotherthrough the clutch assembly 312, thereby bypassing the need for fluidcoupling of the torque converter 300. When the clutch assembly 312 is inthe engaged position, the torsional loads input into the torqueconverter 300 through the front cover 304 are transferred through thesplined outer wall 308 of the front cover 304 and into the splined outersurface 402 of the backing plate 302. The backing plate 302 may thentransfer the torsional forces through the clutch assembly 312 and into adamper 320 that may be coupled to the turbine hub 318. Finally, theturbine hub 318 may transfer the torsional forces out of the torqueconverter 300 through the turbine shaft 114.

A perspective view 400 of the backing plate 302 is shown in FIG. 4.Additionally, a perspective cross-sectional view 500 of the backingplate 302 is shown in FIG. 5. The backing plate 302 can be formed ofsubstantially one material. The material may have a first edge 502, asecond edge 504, and a base portion 506 that extends radiallytherebetween. The first edge 502 and the second edge 504 may be radiallyspaced from one another by the base portion 506. The first edge 502 andthe second edge 504 may also be formed by a bend in the base portion506. For instance, in one non-limiting example the second edge 504 maybe bent a sufficient angle from the base portion 506 to allow the secondedge 504 to be parallel with a rotational axis 508. In one embodiment,it may be advantageous to have a second edge that is parallel to therotational axis 508 because it may allow for some axial movement of thebacking plate 302 without affecting the engagement of the splined outersurface 402 and the splined inner surface 334 of the outer wall 308.

The first edge 502 may also be formed as a bend in the base portion 506that results in a first edge 502 that is substantially parallel to therotational axis 508. The first edge 502 bend may be utilized to addstructural integrity to the backing plate 302 and should not be limitedto a 90 degree bend. One skilled in the art can understand how the firstedge 502 may be any plurality of angles in comparison to the baseportion 506 without affecting the function of the backing plate 302. Forexample, the first edge 502 may be a 180 degree bend.

The base portion 506 may be sufficiently thick to resist substantialdeformation when the clutch assembly 312 is in the engaged position.Further, a surface 510 of the base portion 506 may be sized tocorrespond with the components of the clutch assembly 312. In oneembodiment, the surface 510 corresponds radially with a portion of thedamper 320 that has a friction material coupled thereto. Further, thesurface 510 may also include a friction material (not shown) to aid inthe engagement of the clutch assembly 312. When the clutch assembly 312is in the engaged position, the surface 510 of the base portion 506 maybecome mechanically coupled to the damper 320 through the frictionmaterial.

While the above disclosure for the backing plate 302 describes the baseportion 506 that connects the first edge 502 and a second edge 504, thisdisclosure should not be limited to such a configuration. One skilled inthe art will appreciate that other designs maybe used to achievesubstantially the same result. For example, a support may be inserted toconnect the terminal portion of the first edge 502 and the second edge504. Further, the backing plate 302 may be formed of one solid piecethat does not include any bends. In this embodiment, the cross-sectionof the backing plate 302 may be shaped like a right triangle, with thesplined edge being a right angle to the base portion. One skilled in theart will understand how a plurality of designs similar to thosedisclosed may be used to achieve substantially the same result.

One advantage of the embodiment shown in FIG. 3 may be apparent duringan assembly process of the torque converter 300. More specifically, thedesired clearance for the clutch assembly 312 may be set prior towelding or otherwise coupling the front cover 304 to the rear cover 306.One method of assembly may involve stacking all of the components of thetorque converter 300 on a building table (not shown) so the axis 330 issubstantially perpendicular to the ground as shown by the block diagram600 in FIG. 6.

The method may involve setting the nose hub 322 on the build table 602.Next, the front cover 304 may be placed on the nose hub 322 and coupledthereto 604. The piston 314 may then be placed into a cavity created bythe nose hub 322 and the front cover 606. The clutch assembly 312 andthe damper 320 may then be placed into the front cover 610. Next, thesplined outer surface 402 may be aligned with the splined inner surface334 of the outer wall 308 and be placed therein 612. At least onebearing 324 may then be placed along the nose hub 614 before the turbinehub 318 is placed on and aligned with the nose hub 616. Another bearing324 may be aligned with the turbine hub 618 before a stator assembly 326may be aligned and placed therewith 620. A final bearing 324 may beplaced along the stator assembly 624 before the rear cover 306 can beplaced thereon 626 to substantially complete the assembly.

When the rear cover 306 is placed on the assembly, it may contact thebearing 324 while also contacting the lip 310 of the backing plate 302.The orientation of the torque converter on the build table may allowgravity to force the components into contact with one another. Further,the contact between the lip 310 and the backing plate 302 may compressthe clutch assembly 312 against the piston 314.

Prior to welding or otherwise coupling the rear cover 306 to the frontcover 304, the axial alignment between the front cover 304 and the rearcover 306 may be altered 628. In one non-limiting example, after therear cover 306 has been placed on the torque converter assembly 300,gravity may force the components together as they sit on the buildtable. To alter the clearances between the internal components of thetorque converter 300, the rear cover 306 may be moved axially away fromthe front cover 304 before being coupled thereto 630.

One of the many advantages to the backing plate 302 embodiment shown inFIG. 3 and described above is the ability of the manufacturer to set theclearances of the clutch assembly 312 or bearings 324. For instance, ifthe particular design requires specific clearances for the clutchassembly 312, the rear cover 306 can be coupled to the front cover 304at an axial distance that would accommodate the desired clearances inthe clutch assembly 312. Similarly, if the particular design requiresspecific clearances in the bearings 324, then the rear cover 306 may becoupled to the front cover 304 at an axial distance that accommodatesthe desired bearing 324 clearances.

While exemplary embodiments incorporating the principles of the presentdisclosure have been disclosed hereinabove, the present disclosure isnot limited to the disclosed embodiments. Instead, this application isintended to cover any variations, uses, or adaptations of the disclosureusing its general principles. Further, this application is intended tocover such departures from the present disclosure as come within knownor customary practice in the art to which this disclosure pertains andwhich fall within the limits of the appended claims.

We claim:
 1. A method of assembling a torque converter with a lockupclutch, comprising: providing a front cover, a piston, a clutchassembly, a backing plate, and a rear cover; positioning the piston,clutch assembly, and backing plate at least partially within an interiorregion defined by the front cover; and coupling the rear cover to thefront cover, wherein an axial spacing of the rear cover relative to thefront cover corresponds with spacing of the backing plate from the frontcover.
 2. The method of assembling the torque converter of claim 1,further comprising aligning backing plate splines defined on the backingplate with front cover splines defined in the front cover during thepositioning step.
 3. The method of assembling the torque converter ofclaim 1, further wherein the coupling step comprises axially aligningthe rear cover with the front cover and pressing the backing platetowards the front cover with the rear cover prior to coupling the frontcover to the rear cover.
 4. The method of assembling the torqueconverter of claim 3, further comprising moving the rear cover axiallyaway from the front cover after the pressing the backing plate towardsthe front cover step and prior to coupling the rear cover to the frontcover.
 5. The method of assembling the torque converter of claim 1,further comprising: providing a nose hub, a first bearing, and a turbinehub; and positioning the first bearing between the nose hub and theturbine hub prior to the coupling the rear cover to the front coverstep; wherein, the axial spacing of the rear cover relative to the frontcover corresponds with spacing of the nose hub and the turbine hub. 6.The method of assembling the torque converter of claim 5, furtherwherein the coupling step comprises axially aligning the rear cover withthe front cover and pressing the nose hub towards the turbine hub andmoving the rear cover axially away from the front cover after thepressing the nose hub towards the turbine hub step and prior to couplingthe rear cover to the front cover.
 7. The method of assembling thetorque converter of claim 5, further comprising: providing a statorassembly, a second bearing, and a third bearing; positioning the secondbearing between the turbine hub and the stator assembly prior to thecoupling the rear cover to the front cover step; and positioning thethird bearing between the stator assembly and the rear cover prior tothe coupling the rear cover to the front cover step; wherein, an axialspacing of the stator assembly, the second bearing, and the thirdbearing relative to the front cover corresponds with spacing of the rearcover and the front cover.
 8. The method of assembling the torqueconverter of claim 7, further wherein the coupling step comprises:axially aligning the rear cover with the front cover; pressing thestator assembly towards the turbine hub; and moving the rear coveraxially away from the front cover after the pressing the stator assemblytowards the turbine hub step and prior to coupling the rear cover to thefront cover.
 9. A method for setting a torque converter lockup clutchclearance during assembly of a torque converter, comprising: providing afront cover partially defining an interior region, a piston, a clutchassembly, a backing plate, and a rear cover; placing the piston, clutchassembly, and backing plate in the interior region of the front cover;positioning the rear cover partially within the front cover so the rearcover contacts the backing plate; moving the rear cover axially awayfrom the front cover; and coupling the rear cover to the front cover.10. The method for setting the torque converter lockup clutch clearanceof claim 9, further comprising providing at least one bearing positionedin the interior region, wherein the positioning the rear cover partiallywithin the front cover step further comprises positioning the rear coverpartially within the front cover so the rear cover contacts the at leastone bearing.
 11. The method for setting the torque converter lockupclutch clearance of claim 10, further wherein the moving the rear coveraxially away from the front cover step establishes axial clearances forboth the clutch assembly and the at least one bearing.
 12. The methodfor setting the torque converter lockup clutch clearance of claim 9,further comprising aligning backing plate splines with front coversplines during the placing the piston, clutch assembly, and backingplate in the interior region of the front cover step.
 13. The method forsetting the torque converter lockup clutch clearance of claim 9, furtherwherein the positioning the rear cover partially within the front coverstep is executed while a rotation axis of the front cover issubstantially perpendicular to a level ground and gravity forces therear cover towards the front cover.
 14. A method of assembling a torqueconverter assembly, comprising: placing a nose hub on a build table soan axis of rotation is perpendicular to a level surface of the buildtable; axially aligning a front cover with the nose hub and placing thefront cover onto the nose hub; coupling the front cover to the nose hub;placing a piston and at least one clutch component into the front cover;placing a damper in the front cover in alignment with the clutchcomponent; aligning a backing plate with splines in the front cover andplacing the backing plate into the front cover; placing a first bearingonto a back portion of the nose hub; axially aligning a turbine assemblywith the nose hub and placing the turbine assembly against the firstbearing; placing a second bearing onto a hub of the turbine assembly;axially aligning a stator assembly with the nose hub and placing thestator assembly on the second bearing; placing a third bearing onto ahub of the stator assembly; axially aligning a rear cover with the nosehub and placing the rear cover onto the third bearing; and settingclearances for a clutch assembly by lifting the rear cover a desireddistance away from the front cover before coupling the rear cover to thefront cover.
 15. The method of assembling a torque converter assembly ofclaim 14, wherein the desired distance is a distance that allows theclutch assembly to mechanically transfer torsional force when in anengaged position.
 16. The method of assembling a torque converterassembly of claim 15, wherein the desired distance is also a distancethat allows the clutch assembly to be oriented in a disengaged statewhere torsional force will not be transferred through the clutchassembly.
 17. The method of assembling a torque converter assembly ofclaim 14, wherein the setting clearances for a clutch assembly step alsoincludes setting clearances for the first, second, and third bearing.18. The method of assembling a torque converter assembly of claim 14,wherein the coupling the rear cover to the front cover step involveswelding the rear cover to the front cover.
 19. The method of assemblinga torque converter assembly of claim 14, wherein after the coupling therear cover to the front cover step the torque converter assembly ismounted to a transmission.